Automatic-starting apparatus for metal-vapor rectifiers



B. B. SCHAFER. AUTOMATIC STARTING APPARATUS FOR METAL VAPOR RECTIFIERS. APPLICATION FILED JULY 14.1920.

1,881,077. Patented June 7, 1921.

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BELA BEN-o SCH'L'FER, or BADEN, SWITZERLAND, ASSIGNOR AKTIENGESELLSCHAFT,

TO GLEICI-IRICHTER- OF GLARUS, SWITZERLAND.

Application filed July 14, 1920.

T all whom. it may concern Be it known that I, BiLA BENo SCHKFER, a citizen of the German Realm, residing at No. 39 Schartenstrasse, Baden, Switzerland, have invented certain new and useful Improvements in Automatic-Starting Apparatus for Metal-Vapor Rectifiers, of which the following is a specification.

Metal vapor rectifiers, and more especially rectifiers for large outputs, have over other types of transformers, the advantage that the transformation of the electrical energy is effected without the use of movable parts. As a consequence of this characteristic, the requisite attention is reduced to such a small degree that it would appear possible to install large rectifiers in subfor supervision. In sub-stations however there is the possibility to be reckoned with that the primary current may be interrupted at times, and therefore it may occur that a rectifier which is say to provide light and power for a part of a town, may not be able, in the case of the stoppage of the alternating current, to resume its sending out of toration of its supply of alternating current.

The hitherto known starting apparatuses have necessitated mostly a re-starting by hand. So far as automatic igniting devices have been known, such relates to liquid ignition anodes which are brought by suitable means into contact with the mercury cathode.

In the case of rectifiers for large outputs, it is usual to make the ignition anode of a solid material and to actuate it by means of a solenoid traversed by current. Since in the case of large outputs with comparatively heavy vacuum vessels, the automatic ignition methods employed for small rectifiers, are not directly applicable, there is the neoessity of providing a suitable electrical connection also for ignition anodes solid material.

The present invention relates to an apparatus of this kind wherein the starting is effected automatically by means of the primary current or the direct current.

The solution of this problem is illustrated by way of example in Figures 1 and 2 of the accompanying drawings.

Fig. 1 shows an arrangement according to the invention for rectifiers having an exciter anode and an exciter transformer;

Specification of Letters Patent.

current after rescomposed of Patented June 7, 1921. Serial No. 396,297.

Fig. 2 shows the same for rectifiers without external excitation.

In Fig. 1: T is the main transformer which for the sake of simplicity is shown as being single-phase. In addition to the main anodes a, and a the rectifier 9 comprises also the exciting anodes e and 6 which are supplied in the usual manner from the exciting transformer t. The zero point of the latter transformer is connected through the automatic switch 1' and the resistance 20 to the cathode is of the rectifier; The automatic switch 1 closes and opens the circuit of the ignition electrode a which is actuated by alternating current.

As will be seen from Fig. 1, the ingition electrode 2 may be actuated electromagnetically by means of the solenoid s. The requisite alternating current is taken for example from the exciting transformer t. Vhen the normal exciting current flows through the coils of the switch '1 and through the resistance the switch 1' will interrupt the supply of current to the ignition electrode a.

f the primary current should fail, and consequently the exciting current supplied through to the rectifier should also fail, the circuit of the ignition electrode 2 will close, and on the return of the primary current an intermittent opening spark will become operative between 2 and the cathode 7a owing to the connections which are made after the fashion of interrupters. This in termittent opening spark will remain operative until the exciting current is restored, and the automatic switch 1* interrupts the igniting current the strength of which is suitably adjusted by means of the resistance 20,.

In Fig. 1, p are the primary leads, and 0 are the direct current leads.

As shown in Fig. 2, the apparatus mayalso be employed in cases where rectifiers are used without ignition from the outside. In such a case the alternating current required for actuating the ignition anode a may be taken for instance from the main transformer T. The automatic switch r is in this case preferably influenced through the supply leads Z and the resistance w, by the current traversing the collector bars 0.

hat I claim is 2- 1. A metal vapor rectifier including a fixed metal container, an anode, a cathode, a movable ignition anode and a solenoid 0perated by alternating current to move said ignition anode relatively to the said container, and means for automatically opening the circuit of the energizing coil of said solenoid subsequently to the closure of the primary alternating circuit and automatically 3 u I n a closing said energizing coil clrcuit subsequently to the opening of the primary alternating circuit.

2. A metal vapor rectifier as described in 10 fied current mains and operates to close and open said ignition anode circuit.

In testimony whereof I have signed my 15 name to this specification.

BE'L BENO soHAFER. 

